UEXPAN and VUEXPAN subroutines are used for implicit and explicit solvers respectively. They are used to define incremental thermal strains as functions of temperature, predefined field variables, and state variables. It should be noted, these subroutines are used for models that the thermal strains depend on temperature and/or predefined field variables and/or state variables.
It is important to say that UEXPAN and VUEXPAN subroutines are called twice per material point in each iteration during coupled temperature-displacement and coupled thermal-electrical-structural analyses.
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